1. Field of Invention
The present invention relates to a heat concentrating type self-operated automatic fire valve, which belongs to fields of fire protection and automatic control equipment for temperature reduction.
2. Description of Related Arts
In the conventional fire fighting systems, ionic smoke sensors and glass bulb type sprinkler heads are installed in the room. Due to high investment and lack of flexibility in installation thereof, the conventional fire fighting systems are only utilized in buildings such as high-level hotels, restaurants and office premises. The glass bulb type sprinkler head, which is a disposable device, automatically cracks to spray water. However, when the fire is put out, since the glass bulb type sprinkler head is not capable of switching off automatically, the water still sprays continuously, which not only wastes large quantity of precious water resource, but also causes water logging damages. For instance, secondary disasters due to serious water logging occur in libraries, reference rooms or laboratories for assembling instruments, which causes irretrievable damages. In the references, automatic water spraying without power is achieved by combination structures of magnetic coupling and temperature-memory alloy. However, because the linkage rod which drives the magnetic ring is limited by overall dimension of the piston sleeve, the memory alloy in the original design is required to have relatively large diameter size, which decreases the thrust force in deformation process, and thus the valve can not be opened sometimes. Furthermore, since the valve body is in a straight through type structure, the memory alloy and the valve cap can only be vertical to the valve body. Therefore, it is difficult to install the valve body of the valve above the suspended ceiling, i.e., for connecting with a water pipe. Thus, the thermal sensing elements, such as the memory alloy are installed below the suspended ceiling.